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Polyethylene oxide (PEO) and lithium salts (LiI, LiClO4, and LiCF3SO3) based composite polymer electrolytes have been prepared for different [EO]/[Li] ratio using solution casting method and characterized by x-ray diffraction (XRD), scanning electron microscope, and differential scanning calorimetry (DSC). The electrical measurements have been carried out at different temperatures. XRD patterns, field emission scanning electron micrographs, and DSC clearly depict that amorphous region in the PEO–LiClO4 composite electrolyte with [EO]/[Li]=9 is dominant over the other electrolytes. It has been observed that the electrical conductivity of the PEO–LiClO4 electrolyte is higher than that of the PEO–LiI and PEO–LiCF3SO3 composite electrolytes. It has been also observed that the hoping rate of charge carriers for the PEO–LiClO4 electrolyte is higher than that of the other two electrolytes. The concentration of charge carriers is not thermally activated and the mobility controls the temperature dependence of electrical properties. Scaling of the conductivity spectra has been performed in order to get insight into the relaxation mechanisms. [ABSTRACT FROM AUTHOR]

The ferroelectric properties of sodium nitrite (NaNO2):poly(vinyl alcohol) nanocomposite films prepared by the solvent cast method have been studied. The optimization of the ferroelectric properties of the composite films as a function of the composition gave 50 wt % to be the optimum value. The enhanced remanent polarization was observed in the composite in the frequency range of 10 Hz–1 kHz. The stability of the ferroelectric polarization shows improvement over the pure NaNO2 films. The x-ray diffraction study revealed that the strain is reduced in the composite films. The images of field emission scanning electron microscope showed the nanosize and uniform distribution of particles in 50 wt % composite. The improved values of the polarization and stability have been attributed to the reduced strain in the composite. The ferroelectric phase transition peak was observed in the differential scanning calorimetry (DSC) scan. The ferroelectric phase transition temperature of the composite film obtained from the capacitance-voltage (C–V) measurements agrees well with the DSC measurements. [ABSTRACT FROM AUTHOR]